Tokyo: Japan on Thursday said it will strengthen the surveillance power of its air force, a day after the first-ever intrusion into the country's airspace by a Chinese government aircraft.

"We will take all possible steps for the defense of our airspace," Osamu Fujimura, chief Cabinet secretary, told a news conference, noting that the Defence Ministry is considering "more effective operations" of the Air Self-Defence Force's Airborne Warning and Control Systems, as well as the E-2C airborne early-warning aircraft, Kyodo news reported.

On Thursday, a Chinese government airplane entered Japan's airspace over the Senkaku Islands, the sovereignty of which is claimed by Beijing, for the first time since the ministry started keeping such records in 1958.

Japanese fighter jets were scrambled after the plane was spotted by the country's coast guard at 11:06 am about 15 kilometers south of one of the uninhabited islands in the East China Sea. But Self-Defense Force radar did not pick up the aircraft.

Fujimura said he believes the airspace intrusion by China was aimed at claiming control over the Japanese-administrated islands, adding that the government will "firmly deal with any action that infringes on our country's sovereignty."